Electric brake.



No. 841,710. PATENTED JAN. 22, 1907.

E. o. NEWELL L E. E. DEWSON. ELECTRIC BRAKE.

APPLIGATIONFILBD APR.11.1904.l

INVENTORS ZM 'M/MZ f aux #2mm No. 841,710. PATBNTED JAN. 22, 1907. 1". 0. NEWELL 0E. H. DEWsoN.

ELECTRIC BRAKE.

APPLICAUON FILED APR.11.1004.

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POS/T/ON 777 Tf? @M Pos/WON I7 C A A A A R l n? n I l1' asses I K MMMZM( UNITED STATES- PATENT oEEIoE.

FRANK C. NEWELL- OF WILKINSBURG, AND EDWARD H. DEWSON,y OF

EDGEWOOD PARK,'PENNSYLVANIA,ASSIGNORS TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYLVANIA, A- CORPORATION PENNSYLVANIA.

` ELECTRIC BRAKE.

No. 841,71o.

Specication of Letters `Patent.

Patented Jan. 22, 1907.

T 0 IIJ/Z whom, t Wea/y concern:

Be it known that we, FRANK C. NEWELL,

residing in Wilkinsburg,l and EDWARDv H.-

DEwsoN, residing in Edgewood-Park, in the county of Allegheny and State of Pennsyl- Vania, citizens of the United States, have invented a -certain new and useful Im rovement in Electric Brakes, of which thel ollowing isa speciiication. i I

This invention relates to electric brakes for cars in which themotors are adapted to Ibe connected up as generators in a local brakecircuit; and the principal object of the invention isto provide an improved brakingcontrollerl and circuit connections whereby the current in the brake-circuit may be more readily and eHectually controlled by means of a shunt aroundthe iields of the generators having an automatically-operated opening and closing device Aand manually-operated means for varying the resistance in. said shunt-circuit. Another obj ect is the provision of additional holding and priming points and circuit connections, whereby in certain positions of the braking-controller the line or power current may be utilized for energizing' the brakemagnets or for priming'the iield-s of the generators preparatory to the-closing of the local .generator-circuit; and -still another feature. of the invention comprises an improved atrangement of fuses so located with reference to the shunt-circuit as to permit theblowing out of the connection across the armatureleads on either sideof theshunt-circuit connection.

In the accompanying drawings, Figure 1 is a diagram` showing the contact-points and circuit connections of an ordinary car equipment of two motors and a running-controller with our improved braking-controller applied thereto, and Fig. 2 shows a series of diagrams illustrating the circuits corresponding with the various positions of th'e braking-controller.

Our invention is designed to be used in connection withlany of the usual electric-car equipments, and for the purposes of illustration the same-is shown as applied to the ordinary two-motorequiprnent having astandard series-parallel running-controller Grand reversing-switch D.

According to the preferred construction the braking-controller com rises two movable parts or switches B an K, carrying different sets of movable contacts, the latter being adapted to occu y either one of two positions for running or or braking,vres ectively,

and the switch K being so connecte mechanically with switch B that the movement of the latter from its off position to its 4Jiirst braking position, (marked (1,) or vice versa, (Iierates automatically to throw the switch to its .braking os'ition or to its running position, res ective y.'

' Hereto ore electric-car e uipments have been provided with a bra(l ing'controller adapted to cut o the line vor power current and to connect up the motors to operate as generators in a local circuit containing `brake- ,t magnets, the current being controlled by a .varlable resistance inrsaid circuit. 4. In addition to' lthis" our l.improvement provides a shunt-circuit containing a variable resistance around the iields of the generators when operating to supply current t6 the brake-circuit, said shuntcircuit being o ened or closed by a voltage-regulator, the co1 4 of which is located l inV the 'main brake-circuit, and the variable resistance inthe shunt-circuit being con- ,trolled-f by additional contactbars on the braking-controller. In order that the car ma be held on grades afterbeing stopped an the' generators have ceased to generate current in the brake-circuit, the brakin -con- Atroller may be providedwith additiona con-` tact-points in either its initial position or final position, or both, for supplying line-current to the` brake-magnets, and the line-current -may also be utilized to' prime the fields of the generators in the initial braking position of the braking-controller for the purpose of insuring the rapid building u of current in the localbrake-circuit when t e same is closed by further movement of said braking-controller. All of these features are embodied in our improved braking-controller and circuit connections, which will now be more fully described in detail.

Referring to Fi 1 and considering the brakingicontroller to be in its off position with switch K in position marked running, the reversing-switch D in its forward position, and the running' or power controller C moved roo . be as follows: to the initial bar of the controll'er C, thence to first resistance-bar and lead R throughmain resistance R and by lead R to switch K, thence by contact-bars 22 20 and 23 25 to lead R C and to 19 on reversingswitch D, connecting-bar 4 to lead A through armature A of motor No. 1, lead A A7to re'- versing-switch D, connecting-bar 3 and lead Fl to F C on switch K, conne'cting-bar 21 and lead F M through field F of. motor-No. 1, lead E to connecting-bars on running-controll'er C and lead' 15 -to reversing-switch D, connecting-bar' 2 to lead A2 of armature of motor No. 2, lead A A2 to reversing-switch, vcor-ir-recting-bar 1 lead F2 to F2 C on switch K, connecting-bar 2'4 to field of motor No. 2,` lead E2 to switch K, and by contact-bar 26 to ground G. Further movements of the running-controller C serve to vary the resistance and to connect the motors up in arallel, the o eration of which is well un erstood by t ose familiarl with the art.` When it isdesired to st op or check the speed of the car, the running-controller C is thrown to its ofi position and the braking-controller B is moved to its first braking position, (indicated by the dotted line a.) During this movement the vswitch K -is automatically thrown to its position marked "braking.

The line-current from the trolley -T then Hows throughthepreliminary resistance T R to T Son switch B, cross connections 44 and 43 tolead B which is the same as R through the main resistance R, lead R to switch K, connectmg-bars 16 and 17 and leads F C and F2 C to reversing-switch D, connecting-bars 3 and 1, leads A A and A A2 through the armatures of the motors in'parallel, leads A and A2' back to the reversing-switch, connectingbars 4 and 2' to leads 19 and 15 to R C and 15 C on switch K, to the respective connectingbars47 and 18 to F Mand F2 M, through the fields of the motors in parallel, leads E land E2to switch K, contact-bars 14 and 49 to lead B' C through coil O of blow-out magnet/and throu h coil V of voltage-regulator. to the main rake-magnet coils H, thence by lead B e to switch B, contact-bar 45, lead G through 'coil' O of blow-out magnet, and sec'- ondary coils H of brake-magnet to ground G. This is the. circuit represented in the first diagram of Fig. 2 corresponding to position a. In this position the shunt-circuit around thel fields Iof the motors is open and has no effect,

the line-current beingpassed through the field-coils of the motors toenergize the same preparatory to closing the local brake-circuit.

When the braking-controller is moved to its next braking position, (marked 1),) the contact-points for the line or trolley connection are cut out and the motors are connected up in parallel in the closed localbrake-circuit, the shunt-circuit around the fields also being the brake-circuit. the braking-controller'to position cl serves to closed with no resistance. As the motors are then driven by the momentum of the car, they act as generators, and current iiows from; thearmatures 'of both motors by respective leads A and A2 to reversing-switch D, contact-bars 4 and 2, respectively, to leads 19 and'15, to R C and 15 C on switch K, by

i contact-bars 47 and 18 to F M and F2 M and the fields of the respective motors, thence by leads E and E2, contact-bars 14 and 49 the two branches of thecurrent'unite at switchK in lead B passing through coil O of blowout magnet and coil V of volta e-regulator to the main brake-magnet coil lead B- to bars 30 and 29 of braking-controller B, lead -B, through main resistance R, lead R- to 'switch K, where the'current divides onbars 16 and 17 to F C, andF2 C, thence to F and F2 on reversing-switch, and b contact-bars 3 and 1 to return-leads A A and' A A2 of the respective motors, thus completing the circuit, as indicated in the second diagram (position b) of Fig. 2. In this position at ordinary speeds the current immediately builds up vsufficiently in the *coil V of the voltage-regulator to close the switch P, thereby closing the shunt around the fields of the generators through leads L and L2, which form an equaliz'mg connection across the field-leads ofthe generators, thence by S to'cont'act-bars 39 andl 40 on the braking-controller B and lead S to B+. As there is little or no resistance in the shunt for this osition, the fields of the generators are weakened to prevent an excessive currentbeing built up in the brake-circuit. If a stronger braking-current is desired, the braking-controller may be moved to the next pov siton, (marked 0,) in which all of the circuit connections are the same as in position b, except that the shunt connection 1sbroken at S and closed at S3, thereby inserting a certain amount of ythe shunt resistance S R inthe shunt-circuit and to that extent increasing the strength of the fields and the current in A further movement of o en the shunt connection S2 and includes all o the resistancesS R in the shunt-circuit,

thereby further strengthening the fields bysending throu h the same nearly the entire current of the rake-circuit. Further movement of the brakin -controller to the successive positions ev to serves to cut out successive sections of themain resistance R, as will be readily understood by referring to contactbars 27-to 36 and contact-fingers B to Bg of the braking-controller'B. In the next posi- 4tion (marked m) the bars 37 and 40 are disconnected from contact-fingers 53 and S, thereby entirely opening the shunt-circuit and maintaining the generators in the closed local circuit with the brake-magnets and no resistance, which is theposition for a-maximum braking effect.- In making a full stop the braking-controller is usually brought to IIO this latter position at the final portion of the stop, and then as -the current ceases when the car stops the brake-magnets may not be able f to hold the car in case the stop is made upon a grade. It is therefore desirable to be able to supply the brake-ma nets with current from another source at t 's oint, andwithourimproved braking-contro ler this may be -rent from an auXi iary sourcefof power.

Another Jfeature of our invention relates to the arrangement of the fuse-blocks f and f2,

` which are located in the equalizing crosscon nection between the motor-field leads one on each side ofthe branch connection 'to the shunt S, whereby when the shunt is cut in by the closin of the switch P of the voltageregulator should either fuse blow out by an excessive current through the equalizer the other motor or generator would still remain connected up through the other fusefblock with theshunt for controllingthe s eed of the car. The voltage-regulator is designed to close the `switch P of the shunt as soon as the elds of the generators have built up sulicientlytogenerate the desired current to roperly control the brake-magnets, and for light braking eiie'cts the resistance in the shunt, and corres ondingly the strength of the fields, is manual y controlled by the ositions b, c, and d ofthe braking-control er.

It will now be seen that by means of our improvement the Aline-current may be used in to any of its brakingpositions in which the the iirst. or preliminaryposition of the braking-controller for .both priming the iields of the generators and for energizing the brakemagnets, so that as the controller isfurther moved to its successive positions, includin the shunt-contact connections, the fields Wi be sufliciently energized to rapidly build up a current of sufficient strength to pro erly control the brake and close switch P op the automatic volta e'regul`ator in the shunt. The use ofthe vo tage-regulator insures the building up of the ields of the generators 'to give sufficient current for brakin at all speeds.

l/Vhen the braking-control eris first thrown shunt contact-points are engaged, it will be seen that if there was no means for tern orari ly maintaining the shunt open the fielp the generators would be very slow in building up and generating suiicientcurrent for the brake-circuit; but with o ur improved arrangement, including the automatic volta e' regulator, the switch P of the shunt remains open temporarily, thereby at first diverting sufficient to operate the brake. A

Having now described our invention, what I we claim as new, and desire to secure by Letters Patent, is-

1. The combination'with one or more generators adapted to be driven by the momentum of the car, of a braking-controller for connectmg u the generator or generators 1n a local bra e-circuit', and having vcontactpoints for controlling a shunt around vthe fields of the generators.

2. The combination with one or more generators adapted to be driven by the momentum' ofthe car, of abrakingcontroller for connecting up the generator or'generators in alocal brake-circuit, a maln resistance for the brakecircuit, a shunt-circuit containingx v v a variable resistance around the fields of. the generators, and contact-points on the braking-controller-for varying the resistance. in both the mainbrake-'circuit and the shunt. 3. The combination on. an electric car of one or more motors, a runningecontrolle'r, a braking-controller for'connecting up the mo'- with contact-pointsadapted in one position t0 supply line-current to' -the fields ofthe motorfgenerators and in another position to close a shunt around the fields of the generators.

4'. The combination with -one or more 1110-. tor-generators, of a braking-controller having contact-points adapted in one position to supply current from the line. to thel fields 'of the generators, andin further positionsv toV close a shunt of variableresistance around the fieldsof the generatorsand to control the4 resistance in said shunt. p

5. Thel combination vwith one` or ymore motors and a running-controller of a brakingcontroller for connecting up said motors t0 act as generators -in a local brake-circuit, a

tors to act as generators in a local brake-cir cuit, said braking-controller being provlded IOO brake-magnet and a variable resistance in'v said local circuit, the braking-controllerhav ingy contact-points for controlling-'said resistance and other contact-points in the extreme osition for'supplying line-current to.

the bra e-magnet.

6. The combination of one or more generators adapted to be driven by the momen-f tum of the ca-r, a local brake-circuit, a brak# ing-controller having contact-points for controlling a shunt around the fields of the motors, and anO automatic voltage-regulator located in 'the'local circuit for clos' the shunt when the strength ofthe generate current is tum of thecar, a local brake-circuit, a main ,a shunt containing a I variable resistance around the ields of the generators, a brakingcontroller having contact-points for controlling the resistance in both the main circuit and in the shunt, and an automatic voltageregulator operated by the current in the local circuit for closing the shunt when the cur rent is of sufficient strength to operate the brake-magnet. l

S. The combination of two or more gener- `atorsadapted to be driven by the momentum of the car, -a braking-controller adapted to 4connect said generators up infparallel in a' local brake-circuit with yan equalizer connection across the field-leads, and a shunt around said iields connected to said equalizer, saidbrakng-controller having contact-points for controlling said shunt.

9. rlhe combination of two or more generators adapted to be driven by the momentum of the car, a brakingcontroller adapted to connect said generators up in parallel in a local brake-circuit with an equalizer connection across the 'held-leads, and a shunt around saidelds connected to said equalizer, fuse-blocks located in said equalizer on each side of the shunt connection, said braking-controller havingvcontact-points for con-l trolling said shunt.

In testimony whereof we have hereunto lset our hands.

FRANK o. NEWELD EDWARD n. DEwsoN.

Witnesses:

R. F. EMERY, JAS. B. MACDONALD. l 

